but for me they've always been complimentary.
This is an excellent statement.
I don't train technical train with kettlebells, but I do a few very similar movements with a single loaded dumbbell or big arse plate, to add some fairly dynamic and ballistic movements into my training.
But this is also the issue with kettlebells, ballistic movements like swings, put a fairly rapid loading onto joints (especially backs and shoulders), if not done correctly are somewhat dangerous. Fatigue also an issue with this type of training due to its dynamic nature.
Things commonly seen in kettlebell programs like squats, deadlift, rows, much prefer a barbell; lunges, swings, goblet squats go really well with kettlebells.
Just depends on what your after really? mass or strength traditional lifting vastly superior, for dynamic style training its pretty good, relatively cheap, takes no space... and its been adopted by crossfit, so you cool!